The case of a US federal detainee with potentially infectious rabies challenged public health officials to locate the man’s contacts who might need postexposure prophylaxis (PEP).

The investigation was no small task, as the man was from Guatemala and entered the United States illegally last year, presumably through Mexico. While in federal custody, he had contact with law enforcement officers, health workers, and other detainees in 4 detention facilities, a medical clinic, and 2 hospitals. He died about a month after being apprehended—2 days after his rabies diagnosis was confirmed.